Log feeding and turning machine

ABSTRACT

Logs being fed by opposing feed rolls can be simultaneously rotated in one direction or the other by selective tilting of the opposing rolls in respectively opposite directions. The amount of rotation during longitudinal feed of the log can be controlled by returning the rolls to the untilted or normal feed positions after the desired rotational movement is achieved. Tandem interconnected cylinder compartments and associated pistons utilize hydraulic pressure from a source as a coupling medium to effect tilting of a roll in either direction and back from a normal position through simple two-position four-way valves with neutral-seeking control means operating the valves, such that release of the controller by the operator causes the feed rolls to return to normal position. Automatic sensing of log position in relation to the feed path releases the grip on the logs by retracting the rolls should the log become temporarily misaligned, and restores the grip on the logs for resumption of feed once the log settles back to the normal position.

United States Patent 91 [451 Dec. 17 1974 Albrecht 1 1 LOG FEEDING AND TURNING MACHINE [75] Inventor: Dennis W. Albrecht, Seattle, Wash. [73] Assignee: Stetson-Ross Machine Company,

Inc., Seattle, Wash.

[22] Filed: Oct. 5, 1972 [21] Appl. No.: 295,207

[52] US. Cl. 214/339, 226/177 [51] Int. Cl B65h 51/26 [58] Field of Search 214/338, 339; 104/166; 226/177, 193

[56] References Cited UNITED STATES PATENTS 2,726,691 12/1955 Harwood 214/339 3,490,665 1/1970 Jonsson 226/177 3,517,844 6/1970 Wloszek 214/338 3,713,555 1/1973 Wloszek 214/339 Primary ExaminerRobert .1. Spar Assistant Examiner-John Mannix Attorney, Agent, or Firm-Christensen, OConnor, Garrison & Havelka 5 7 ABSTRACT Logs being fed by opposing feed rolls can be simultaneously rotated in one direction or the other by selective tilting of the opposing rolls in respectively opposite directions. The amount of rotation during longitudinal feed of the log can be controlled by returning the rolls to the untilted or normal feed positions after the desired rotational movement is achieved. Tandem interconnected cylinder compartments and associated pistons utilize hydraulic pressure from a source as a coupling medium to effecttilting of a rollin either direction and back from a normal position through simple two-position four-way valves with neutral-seeking control means operating-the valves, such that release of the controller by the operator causes the feed rolls to return to normal position. Automatic sensing of log position in relation to the feed path releases the. grip on the logs by retracting therolls should the logbecome temporarily misaligned, and restores the grip on the logs for resumption of feed once the log settles back to the normal position.

15 Claims, 10 Drawing Figures PATENTEB DEC! 7 I974 SHEET 2 BF 4 PATENTELSEBI mu SHEET 30F 4 aw wmw w 1 I LOG FEEDING AND TURNING MACHINE BACKGROUND OF THE INVENTION The rotational positioning of logs for proper engage-.

ment by a feed conveyor, for inspection or for sawing, canting, or for otherwise processing the logs to afford maximum or best yield, typically has required stopping the logs in their movement through a mill in order to effect the required rotational movements. The procedure thereby retarded production. Also apparatus available to perform this function has not been as'fully reliable or adaptable as is necessary to, operate consistentlywith logs of the varying shapes and sizes encountered. Moreover, the log rotating apparatus usually occupied floor space representing a substantial part of the length of the log andthus complicated or added unduly to the cost and space requirements of installation.

A broad object of the present invention is to devise a combined log feeding and log turning apparatus which does not require interruption of the endwise feeding'motion of the log in order to effect turning it into any desired position and moreover which involves relatively simple and compact apparatus requirements. Logs may be fed and rotated individually in immediate end to end succession by the novel apparatus.

In addition to turning the log while feeding it endwise, apparatus of the invention maintains the log in any of the different rotational positions to which it may be assigned by the combined feeding and turning members as purely longitudinal feed motion is required.

Furthermore, the novel mechanism permits selectively rotating the log in either direction as it is being fed endwise and of doing so with the log being fed or moved endwise in either direction.

As a further objective, the invention affords a means which permits arate of turning of the log which is related to the rate of endwise feed of the log.

Still another advantageous characteristic of the novel mechanism lies in its ability to rotate the log while feeding it without the log turning forces materially interferring with the axial alignment of the log in relation to the feed path. Thus, the members acting on the log to turn it about its axis while it is being fed endwise also cooperate insuch a way generally as to avoid lifting or cant ing the log in relation to its feed path. However, there is also automatic provision for releasing and then regripping the log should an irregularly shaped log cause interaction with guides or feed members so as to produce temporary misalignment from the feed path.

Another object of this invention is to devise automatic controls for actuation of the combined log feeding and log turning members such that the members move from initially separated positions, for receiving the log, into log engaging positions accommodating logs of various shapes and sizes, and thereupon for maintaining continuous and steady engaging pressure on the log regardless of variations in diameter, protuberances, or other irregularities in the logs. Furthermore, a single control means is provided for the combined feeding and turning members which in a simple and reliable manner provide an automatic selfcentering return which restores the combined feeding and turning members to a neutral position for pure endwise feeding motion imparted to the log, thereby reducing the operators tasks to the simple'functions of selecting feed direction and applying selected amounts of turning motion to the log until the correct rotational position is reached.

BRIEF SUMMARY OF TI-IE INVENTION In its disclosed form, the novel mechanism features parallel opposing driven log feedrolls, preferably two at one side of the log .at' spaced locations along its.

one side in one direction of tilt, and the rolls on the op.-

posite side in the opposite direction of tilt so as to apply to the log both cooperative rotational torque producing turning forces and cooperative endwise feeding forces.

SUMMARY OF INVENTION Preferably, the feed rolls on opposite sides of the log are mounted on respective supports movable toward and from each othertransversely to the feed path by fluid actuated positioners normally separating the rolls to receive a log between them and automatically controlled by the presence of the log approaching or reaching the rolls to close the rolls on the log for drivingly engaging and feeding the same, and for combined feeding and turning of the same. A photocell switch device or other sensor responsive to log presence is so positioned in relation to the log feed path that any temporary misalignment of the log from that path is sensed to actuate the positioners reverselyand thus release the log temporarily to permit its return to aligned position, which in turn is sensed for causing reengagement of the log and resumption of feed and/or turning movement. Preferably one of the positioners is hydraulically actuated and the other pneumatically actuated, the former for transverse positional indexing of the log and the latter for maintaining yieldable roll pressure on the log accommodating variations 'in' diameter or shape of the log portions contacting the rolls.

Still other features of the invention reside in the means for selectively and directionally tilting the combined feed and turning rolls employing fluid actuators of the piston and cylinder type wherein tandemly acting cylinder compartments cooperating with associated hydraulic pistons to cause tilting selectively in either direction to and from a neutral position through a predetermined displacement. Coordinated control valves for operating the opposing roll tilt actuators respond simultaneously to the selected settings of a neutral-seeking controller which the operator manipulates. The hydraulic circuitry is arranged so that upon release of the controller, the rolls are automatically returned to their normal or parallel upright positions without further operator attention. The hydraulics and associated actuator mechanism are advantageously simplified by the maintenance of source pressure in the cylinder compartments' between times of tilt actuation as well as during tilt actuation as a means of affording mechanical interlock between the tandem sections such that one section may be effective to tilt the associatedcylinder in one direction through the coupling link of the other section and vice versa.

These and other features, objects, and advantages of the invention will become more fully evident as the de- DESCRIPTION OF DRAWINGS FIG. 1 is an isometric view of the illustrated apparatus for effecting combined feeding and tilting of logs in accordance with the invention.

FIG. 2 is a simplified operating diagram illustrating the principle of combined feeding and turning action of the rolls tilted one way so as to rotate the log in one direction;

FIG. 3 is a similar diagram illustrating the rolls tilted in the opposite direction so as to rotate the log reversely.

FIG. 4 is an elevation view of the machine depicted in FIG. 1 seen along the direction of the feed path, with the log appearing between the rolls.

FIG. 5 is a detail illustrating the construction of one of the rolls, and its associated rotational and tilting sup port and drive motor.

FIG. 6 is a plan view of the machine.

FIG. 7 is a transverse sectional view taken on line 77 in FIG. 6 illustrating the feed roll stationed on one side of the feed path.

FIG. 8 is a transverse sectional view taken on line 88 in FIG. 6 illustrating the dual feed rolls stationed on the opposite side of the feed path.

FIG. 9 is a hydraulic diagram illustrating the preferred means for driving and tilting the cooperating rolls.

FIG. 10 is a control diagram illustrating the preferred means for automatically operating the roll carriage positioners so as to engage and disengage logs entering and leaving the rolls.

DESCRIPTION WITH REFERENCE TO DRAWINGS stationed at an intermediate position along the feed path adjacent the opposite side of the log to drivingly engage the log. These rollers are suitably serrated or otherwise surfaced to provide efficient tractional engagement with the log. They are mounted to turn on normally upright parallel axes, the two rollers 16 and 18 in a first vertical plane parallel to the feed path and the roller 20 in a second plane parallel to the feed path.

Roller 18 is rotationally supported on a yoke 21 carried on a horizontal shaft 22 rotatably mounted in a support carriage 24 to turn on a horizontal axis transverse to the feed path FF. Roll 16 is similarly mounted on a yoke 26 and associated support shaft 28 correspondingly mounted on the support carriage 24. In turn,'roll 20 is likewise mounted on a yoke-30 with a support shaft 32 journalled in a support carriage 34.

Carriage 24 is positioned by a hydraulic piston and cylinder jack 36 secured at one end to the base frame 12 and at its opposite end, by way of lug 38, to the carriage 24 so as to advance the drive rolls 16 and 18 toward and from driving engagement with the log L. Hy-

draulic actuator 36 preferably has arelatively short stroke such as eight inches and positions the carriage 24 either in a definite retracted position or in a definite advanced position, in which latter position the rolls l6 and 18 index the log transversely to the feed path for proper registry with auxiliary apparatus such as saws, chippers or other mechanism (not shown) to or from which the log is being fed along feed path F-F.

Carriage 34 is movable toward and from logengaging contact of its roll 20 by means of pneumatic piston and cylinder jack means 40 secured at one end to the base frame 12 and at its opposite end by way of coupling 42 to the carriage 34. This pneumatic jack preferably has a relatively long stroke such as three feet between limit positions. 7 1

Feed roll 20 is driven rotationally by hydraulic motor 20a mounted on top of yoke 30. Feed rolls l6 and 18 path.

Pressure maintaining the rolls in tractional engagement with the log clamped between them is exerted by the pneumatic piston and cylinder unit 40 which is normally supplied with air pressure available in most saw mills and other log processing plants. Irregularities in log diameter or shape causing reaction pressures on the drive rolls and thereby on the respective carriages 34 and 24 are accommodated by the ability of the pneumatic jack unit to expand and contract while maintaining clamping or driving engagement pressure of the rolls against the log.'The hydraulic jack unit 36 serves essentially as a rigid lock in this instance.

Any of various suitable base frame structures may be used and the details of the support carriages 24 and 34 may also vary. In the presently preferred and illustrated embodiment the base frame 12 has longitudinal members extending transversely of the feed path which are engaged by suitable captive slide shoes comprising part of the respective carriages and which permit the carriages to slide lengthwise of the base frame members in response to positioning forces exerted by the respective jacks 36 and 40.

As shown in FIG. 5, roll 20 comprises a cylindrical member journalled between the arms of yoke 30. This cylindrical member has a lower end which is rotation ally mounted in the lower yoke arm by way of a shaft pin 20b and an upper end with an apertured end plate 20c which receives machine screws 20d securing the fitting 20e therein which is fixedly mounted on the shaft 20f of the hydraulic drive motor 20a. The latter is mounted on the upper arm of bracket 30. Bracket 30 in turn is mounted on shaft 32 by means of fitting 32a serving as a rigid support for the bracket. The shaft-32 is rotatably received in a journal sleeve 32b mounted on support carriage 34. Thus the roller 20 may be tilted about the axis of shaft 32 with the latter journalled in sleeve 32b. Moreover it .will be evident that the tilting function is independent of the driving or rotating function of the roller 20 effected by hydraulic motor 20a. The feed roll' 20 may be rotated in either direction as it is tilted in either direction. The other feed rollers are similarly constructed, mounted and driven.

The rotational support fitting 32a for feed roll has an arm 32c projecting from one side thereof which is connected to one end of a hydraulic piston and cylinder jack device 52 whose opposite end is anchored at 52a to a stationary point on the carriage 34, with the jack extending in the generally upright position. Thus extension and retraction of the hydraulic jack 52 effects tilting of the rotational axis of feed roll 20 about the transverse axis of its support shaft 32 (FIG. 7). The hydraulic jack 52 is designed to have one limit position of extension in which the roll 20 is tilted at 45 to the vertical in one direction, and an opposite limit position of contraction wherein the roll is tilted at 45 in the opposite direction. Thus the feed roll 20 can be tilted through approximately 90, 45 on either side of the upright or neutral position.

Similarly feed rolls 16 and 18 can be tilted conjointly through the same angular range as the roll 20, although they are tilted oppositely from the roll 20 in any given position of the latter. Tilting of the feed rolls 16 and 18, as depicted in FIG. 8, is effected by means of a hydraulic piston and cylinder jack unit 54 anchored at one end to the carriage 24 at point 540 and connected at its opposite end to crankarm 56 dependingly projecting from the rotational support fitting 58 for the yoke 26 which carries feed roll 16. A similar crankarm 60 projects dependingly from the rotational support fitting 62 carrying the yoke 21. The arms 56 and 60 are pivotally interconnected by a link 64 such that when the hydraulic actuator 54 expands or shortens in length to control tilting of the rolls l6 and 18 the two arms 56 and 60 swing conjointly.

Referring to FIG. 9, the tilting and driving functions applied to the feed rolls are performed by hydraulic pressure supplied by pump P driven by motor M and drawing fluid from a reservoir 100. Pressure conduit 102 from pump P is selectively connectable to one side or the other of the hydraulic roll drive motors 16a, 18a and 20a by means of the three-position four-way valve 104 which also controls the flow from the motors to the return line 106 leading to thesump 100. Solenoid controlled valve 104 is actuated selectively by a controller 108 having alternatively selectable contacts 108a and 108b for energizing one solenoid or the other of valve 104 in order to reverse the drive direction of the feed rolls simultaneously. In the neutral position of controller 108 the valve 104 cuts off flow to the hydraulic motors driving the rolls.

Flow control valves (FCV) 110 in the respective conduits leading to each side of the roll drive motors are of the adjustable type enabling all of the motors to be driven from the same pressure source and adjusted to operate at substantially identical speeds in either direction of rotation of the motors so as to obtain maximum cooperative driving efficiency.

Tilting of the roll support yokes and thereby of the 6 52f which maintains the piston stationary. Piston 52d is connected by a rod 523 to the crankarm 32c associated with the support for roll 20.

In the upright or normal operating position of the feed roll 20 wherein purely longitudinal feed forces are applied to the log, piston 52c and cylinder compartments 52a and 52b are so positioned relatively that the two pistons occupy corresponding ends of .the respective compartments. This normal position of feed roll 20 -is effected in the described limiting positions of the pistons in relation to the cylinder compartments which are established by the steady pressure of pump P delivered to the upper ends of the respective compartments 52a and 52b through the respective conduits 52a and 52b In effect the pressure of the pump P thereby locks the feed roll 20 in its normal upright driving position. Now in order to tilt the rotational axis of roll 20 clockwise, valve 124 is reversed so as to deliver pressure fluid through conduit 52a" to the lower end of compartment 52a and exhaust fluid from the upper end of the compartment, thereby to actuate the piston 520 to its upper limiting position in the compartment 52a. When later it is desired to return the clockwise-displaced feed roll to its normal upright position the setting of valve 124 is again reversed and the piston 520 is driven downwardly to its lower limiting position. Meanwhile the cylinder means comprising the compartments 52a and 52b remains stationary since pressure from pump P is maintained in the upper portion of compartment 52b and forms a rigid coupling between the cylinder means and stationary frame point to which piston 52d is connected.

Now in order to tilt the feed roll 20 counterclockwise the setting of valve 122 is reversed in order to deliver pump pressure through conduit 52b to the lower end of compartment 52b and exhaust pressure fluid from the upper end of compartment 52b, whereby, with piston 52d anchored stationary, the cylinder means itself is displaced downwardly. Inasmuch as the upper end of compartment 52a remains under pressure from the pump P with the prevailing setting of valve 124, such downward displacement of the cylinder means is accompanied by physical downward displacement of the piston 52c and thereby of the crankarm 320 in order to tilt the roll 20 counterclockwise. In order to return the roll from its counterclockwise displaced position to its normal upright operating position the setting of valve roll rotation axes from the normal upright position (depicted in FIG. 9) in one direction or the other is accomplished selectively by operation of a neutral-seeking controller 120, four two-position, four-way valves 122, 124, 126 and 128, and the two hydraulic actuator jacks 52 and 54. For example, referring to drive roll 20, hydraulic actuator 52 comprises a cylinder means having tandemly arranged compartments 52a and 52b, with a piston 52c slidably received in compartment 520 and a piston 52d slidably received in compartment 52b. Piston 52d is connected by a rod 52e to a frame point at 122 is again reversed and the cylinder means is displaced upwardly in relation to piston 52d, and with it piston 520 is likewise displaced, utilizing pressure of the pump P in the upper end of compartment 52a again as a rigid physical coupling. It may thereby be seen that alternate reversals of the two valves 122 and 124 acting through the medium of the hydraulic piston and cylinder unit 52 enables reliable and definite positioning of the feed roll 20 in terms of tilting ineither direction from its normal upright position and tilting the same back again to its normal upright position.

In like manner, selective reversal of the settings of I the valves 126 and 128 coacting with the hydraulic piston and cylinder unit 54 causes controlled conjoint tilting of the feed rolls 16 and 18 through the same angular range and in the same manner. Such controlled actuation of the valves 128, 126, 124, and 122 is effected by the controller which is a neutral-seeking controller normally positioned as shown in FIG. 9. The valves themselves are also self-retuming valves employing spring or equivalent means to position them relatively so as to maintain the hydraulic jacks 52 and 54 in the settings depicted in FIG. 9, in the absence of solenoid energization from controller 120.

Controller 120 has a first contact 120a, selective engagement of which by displacement of the controller 120, simultaneously energizes the solenoids or valves 124' and 128 so as to tilt the roll 20 clockwise and the rolls l6 and 18 counterclockwise. When the controller 120 is released its return springs cause it to seek the neutral position'and the return springs on the valves 124 and 128 cause them to seek their normal positions so as to return the respective rolls to their normal upright feed positions.

Similarly, controller 120 has a second contact l20b which causes energization of the solenoids for valves 122 and 126 so as to displace the feed roll 20 counterclockwise and the feed rolls 16 and 18 conjointly clockwise. Again, release of the controller 120 causes it to seek its neutral position and the return springs of the valves 122 and-126 cause them to return to their normal positions so as to positively tilt the feed rolls back to their normal upright positions. Adjustable feed control valves 140 in the hydraulic lines between the control valves 122, 124, 126 and 128 and the respective ends of the cylinder compartments permit adjustments in the rates of flow of fluid in one direction through the valves while affording substantially unimpeded flow in the opposite direction. By means of these flow control valves 140 it is possible to synchronize or coordinate the tilting rates of the respective feed rolls so they all act together.

It will be appreciated that the hydraulic diagram of FIG. 9 is somewhat simplified in terms of a practical operating system in that pressure limiting valves and other apparatus may be added. Likewise it will be seen that the controllers 108 and 120 are interconnected by a means 160, which is to suggest that they may be incorporated in a conventional universal motion type of controller so that the operator need but grasp a single handle with which to control direction of feed motion applied to the log and direction of tilt of the feed rolls so as to rotate the log in either direction as it is being fed in either direction and to permit terminating the rotation of the log at any point without terminating the feed motion.

In FIG. 10 the control system for operation of the hydraulic positioner 36 and pneumatic positioner 40for the roll carriages is depicted. In this instance the control is automatic and the key to the controller lies in a sensing means such as the photocell'200 and associated light source 202 placed to sense the proper positioning of the log in the feed path F-F, and thereby in relation to the cooperating feed rolls 20, 16 and 18. In practice the light beam produced by the light source 202 impinging on the photocell 200 is disposed intersectingly across the feed path F-F as shown in FIG. 4 at a level just above'the support level provided by the guide roller 10 so that the light beam will be interrupted by a log of small diameter. Yet should a log being fed tend to lift appreciably off the guide roller 10 and thereby out of proper feed position the light beam will be restored and the photocell will sense this condition. A switch 204 actuated by the photocell 200 automatically operates the hydraulic valves 206 and 208 which control extension and retraction of the respective actuators or positioners 40 and 36. Under normal conditions, that is without a log present in the feed path between the rollers 20 and 16l8, air under pressure from the compressor 210 flows through valve 206 in such a direction as to retract the roll 20 to its maximum offset from the feed path FF. Similarly under these same conditions hydraulic pressure from pump P through control valve 208 acts to contract the hydraulic positioner jack 36 and thereby retract the rolls 16 and 18 the maximum dis tance from feed path FF. Thus the separation of the roll 20 on the one side and rolls l6 and 18 on the other side permits a log of any size to enter into the space between the rolls by advancement along the feed path FF from a suitable input device (not shown). The in-- stant such a log L reaches the photocell beam, however, it interrupts that beam. This condition is sensed by the photocell 200 and actuates the switch 204 to reverse the settings of valves 206 and 208. As a result the actuators and 36 are extended to bring their respective rolls into driving engagement with the opposite sides of the log L. By positioning of the photocell ahead of the drive rolls, a time delay should be incorporated in the system by any suitable means (not shown) causing the rolls to engage the log at approximately the time the log advances to the position where it can be first clamped between the rolls.

It will now be evident that the apparatus disclosed affords a means of accomplishing the desired objectives. It enables logs of varying sizes and shapes to be fed in endwise succession and turned by desired amounts selectively in either direction during such feed, with the feed occurring in either direction. The operator manipulating the controllers 108 and 120 selects the direction of feed and also selects the amount anddirection of rotation that may be applied to each log. This may be done either for inspection purposes or to present the log in an optimum rotated position for further processing as it leaves or while it is passing through the appararoll 20 is tilted clockwise and rolls l6.and 18 counterclockwise, component cooperable forces applied to the log resolve into longitudinal feed forces cooperable to advance the log, and rotational forces cooperable to rotate the 'log in one direction. Likewise counterclockwise tilting of roll 20'and clockwise tilting of rolls 16 and 18 in their respective planes parallel to the feed path, with the rolls continuing to turn in driving engagement with the log, effect reverse rotation of the log. The human operator manipulating the controller simply holds it in the selected position for a period of time which permits the log to rotate through the desired angle and thereupon releases the controller. The controller then returns to its normal position and the associated control valves return to normal position causing the rolls to return to their nonnal upright positions to resume applying purely longitudinal feed forces to the log. t

It may be seen that use of a single roll 20 at an intermediate position opposite the two rolls l6 and 18 represents a reduction to the simplest form of the apparatus using the fewest number of rolls that provide stable log engagement. Four or more rolls are not necessary. Moreover, only two rolls, one located directly opposite the roll 20, for instance, tend to misalign the log in relation to the feed path. That this is true may be seen by noting that tilting of the two rolls in opposite directions while they are pressed against the sides of a log (a small log, for example) would cause the clamping forces to be applied to the log at longitudinally offset points, resulting in a torque which would tend to swing the log in a horizontal plane. However, by employing the single roll at an intermediate position, opposite rolls 16 and 18, the clamping forces applied to the sides of the log are neutralized and the log remains undisturbed in its position of alignment with the feed path.

It will also be noted that tilting of the rolls to exert rotational forces on the log produces lifting force on one side and depressing force on the opposite side of the log. Thus, these forces tend to neutralize each other. Any deviation or offset of the log from the feed path for whatever reason is sensed by the photoelectric cell 200 which temporarily releases the log for a time sufficient to permit it to settle back into normal alignment with the feed path before the log is again clamped between the rolls and log feed resumed.

These and other aspects of the invention will be evident fromthe disclosure as will the fact that a number of variations and modifications may be employed within the coverage of the claims which follow.

What is claimed is:

1. Apparatus for endwise feeding and rotational positioning of a log during feeding in a feed path comprising means to support and guide a log for longitudinal movement along a feed path, mutually opposing feed rolls, opposing support means disposing the respective feed rolls with their respective rotational axes in normal feed positions substantially parallel to each other and transverse to the feed path adjacent opposite sides of a log in the feed path, including positioning means cooperating with the respective support means for positioning the rolls in driving engagement with the log, the positioning means for the rolls on opposite sides of the log being yieldable relative to each other transversely to the log to accommodate varying log contours with the rolls in said driving engagement, drive means for rotating the rolls about their respective axes to apply cooperative feeding forces to the log engaged by the rolls soas to move it'endwise in the feed path, and tilt means selectively operable for tilting the opposing driven rolls out of their normal feed positions in respectively opposite directions by substantially equal amounts in respective planes parallel to the feed path so as to apply to the log cooperative log rotating forces accompanying ccoperative endwise log feeding forces both applied by roll rotation.

2. The apparatus of claim 1 wherein the opposing rolls comprise two generally cylindrical rolls spaced apart along one side of the log in a plane parallel to the feed path and at least one generally cylindrical roll at the opposite side of the log. y

3. The apparatus of claim 2 wherein the lastmentioned roll is positioned intermediate said two rolls alongthe feed path.

4. The apparatus of claim 1 wherein the tilting means are operable to tilt the opposing rolls selectively in either direction so as to rotate the log one way or the other as it is being fed.

5. The apparatus of claim 4 wherein the drive means for the rolls are selectively operable in either direction of rotation so as to feed the log endwise in either direction along the feed path.

6. The apparatus of claim 5 wherein the positioning means are operable soas to advance the rolls into driving engagement with the log and to retract the rolls clear of the log, and further including log sensing means positioned to be responsive selectively to presence of the log in the feed path and to deviation of the log from such feed path, said sensing means being operatively connected to the positioning means so as to effect retraction of the feed rolls from the log in response to such log deviation and to restore the feed rolls into driving engagement with the log upon the log reassuming suchposition relative to the feed path.

7. The apparatus of claim 1 wherein the positioning means are operable so as to advance therolls into driving engagement with the log and to retract the rolls clear of the log, and further including log sensing means positioned to be responsive selectively to presence of the log in the feed path and to deviation of the log from such feed path, said sensing means being operatively connected to the positioning means so as to effect retraction of the feed rolls from the log in response to such log deviation and to restore the feed rolls into driving engagement with the log upon the log reassuming such position relative to the feed path.

8. The apparatus of claim 7 wherein the positioning means associated with at least one of said support means includes pneumatically actuated force applying means maintaining driving pressure of the rolls against the log and resiliently yielding to transverse reaction displacement pressures produced on the associated support means when surface variations on the log are encountered. I

9. The apparatus of claim 8 wherein the positioning means for moving the other of the roll support means includes hydraulically actuated force applying means and associated apparatus operable to actuate the same, so as to positionally index the log transversely to the feed path, said associated apparatus including means resisting reactive displacement of the last-mentioned roll support means through said hydraulically actuated force applying means in response to log surface variations encountered.

10. The apparatus .of claim 9 wherein the tilt mean comprises floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the roll support means to permit tilting of the roll thereof, means physically anchoring the othersuch piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the firstmentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for positioning the drive roll with its axis substantially perpendicular to the feed path, a first altemative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, thereby to enable selectively tilting the associated feed roll in one direction or the other, said valve means further including neutralseeking means acting automatically thereon for restoring the normal set of connections and thereby the rolls to normal position.

11. The apparatus of claim 1 wherein the tilt means comprises floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the roll support means to permit tilting of the roll thereof, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with'associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the firstmentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for positioning the drive roll with its axis substantially perpendicular to the feed path, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, thereby to enable selectively tilting the associated feed roll in one direction or the other, said valve means further including neutralseeking means acting automatically thereon for restoring the normal set of connections and thereby the rolls to normal position.

12. The apparatus of claim 1 wherein the positioning means associated with at least one of said support means includes pneumatically actuated force applying means maintaining driving pressure of the rolls against the log and resiliently yielding to transverse reaction displacement pressures. produced on the associated support means when surface variations on the log are encountered.

13. The apparatus of claim 12 wherein the positioning means for moving the other of the roll support means includes hydraulically actuated force applying.

means and associated apparatus operable to actuate the same, so as to positionally index the log transversely to the feed path, said associated apparatus including means resisting reactive displacement of the lastmentioned roll support means through said hydraulically actuated force applying means in response to log surface variations encountered.

14. In apparatus to effect displacement of an element selectively between a normal intermediate position and either of two other positions oppositely offset from said normal position, floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the element to permit displacing the element thereby, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the firstmentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit-position relative to the stationary piston for normal positioning of the element, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second altemative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment.

15. In apparatus to effect displacement of an element I choring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the firstmentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for normal positioning of the element, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective, ends of one such cylinder compartment, and'a second altemative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, said valve means further including neutral-seeking means acting automatically thereon for retaining the normal set of connections and thereby the element to normal position. 

1. Apparatus for endwise feeding and rotational positioning of a log during feeding in a feed path comprising means to support and guide a log for longitudinal movement along a feed path, mutually opposing feed rolls, opposing support means disposing the respective feed rolls with their respective rotational axes in normal feed positions substantially parallel to each other and transverse to the feed path adjacent opposite sides of a log in the feed path, including positioning means cooperating with the respective support means for positioning the rolls in driving engagement with the log, the positioning means for the rolls on opposite sides of the log being yieldable relative to each other transversely to the log to accommodate varying log contours with the rolls in said driving engagement, drive means for rotating the rolls about their respective axes to apply cooperative feeding forces to the log engaged by the rolls so as to move it endwise in the feed path, and tilt means selectively operable for tilting the opposing driven rolls out of their normal fEed positions in respectively opposite directions by substantially equal amounts in respective planes parallel to the feed path so as to apply to the log cooperative log rotating forces accompanying ccoperative endwise log feeding forces both applied by roll rotation.
 2. The apparatus of claim 1 wherein the opposing rolls comprise two generally cylindrical rolls spaced apart along one side of the log in a plane parallel to the feed path and at least one generally cylindrical roll at the opposite side of the log.
 3. The apparatus of claim 2 wherein the last-mentioned roll is positioned intermediate said two rolls along the feed path.
 4. The apparatus of claim 1 wherein the tilting means are operable to tilt the opposing rolls selectively in either direction so as to rotate the log one way or the other as it is being fed.
 5. The apparatus of claim 4 wherein the drive means for the rolls are selectively operable in either direction of rotation so as to feed the log endwise in either direction along the feed path.
 6. The apparatus of claim 5 wherein the positioning means are operable so as to advance the rolls into driving engagement with the log and to retract the rolls clear of the log, and further including log sensing means positioned to be responsive selectively to presence of the log in the feed path and to deviation of the log from such feed path, said sensing means being operatively connected to the positioning means so as to effect retraction of the feed rolls from the log in response to such log deviation and to restore the feed rolls into driving engagement with the log upon the log reassuming such position relative to the feed path.
 7. The apparatus of claim 1 wherein the positioning means are operable so as to advance the rolls into driving engagement with the log and to retract the rolls clear of the log, and further including log sensing means positioned to be responsive selectively to presence of the log in the feed path and to deviation of the log from such feed path, said sensing means being operatively connected to the positioning means so as to effect retraction of the feed rolls from the log in response to such log deviation and to restore the feed rolls into driving engagement with the log upon the log reassuming such position relative to the feed path.
 8. The apparatus of claim 7 wherein the positioning means associated with at least one of said support means includes pneumatically actuated force applying means maintaining driving pressure of the rolls against the log and resiliently yielding to transverse reaction displacement pressures produced on the associated support means when surface variations on the log are encountered.
 9. The apparatus of claim 8 wherein the positioning means for moving the other of the roll support means includes hydraulically actuated force applying means and associated apparatus operable to actuate the same, so as to positionally index the log transversely to the feed path, said associated apparatus including means resisting reactive displacement of the last-mentioned roll support means through said hydraulically actuated force applying means in response to log surface variations encountered.
 10. The apparatus of claim 9 wherein the tilt means comprises floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the roll support means to permit tilting of the roll thereof, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the first-mentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a correspondinG limit position relative to the stationary piston for positioning the drive roll with its axis substantially perpendicular to the feed path, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, thereby to enable selectively tilting the associated feed roll in one direction or the other, said valve means further including neutral-seeking means acting automatically thereon for restoring the normal set of connections and thereby the rolls to normal position.
 11. The apparatus of claim 1 wherein the tilt means comprises floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the roll support means to permit tilting of the roll thereof, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the first-mentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for positioning the drive roll with its axis substantially perpendicular to the feed path, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, thereby to enable selectively tilting the associated feed roll in one direction or the other, said valve means further including neutral-seeking means acting automatically thereon for restoring the normal set of connections and thereby the rolls to normal position.
 12. The apparatus of claim 1 wherein the positioning means associated with at least one of said support means includes pneumatically actuated force applying means maintaining driving pressure of the rolls against the log and resiliently yielding to transverse reaction displacement pressures produced on the associated support means when surface variations on the log are encountered.
 13. The apparatus of claim 12 wherein the positioning means for moving the other of the roll support means includes hydraulically actuated force applying means and associated apparatus operable to actuate the same, so as to positionally index the log transversely to the feed path, said associated apparatus including means resisting reactive displacement of the last-mentioned roll support means through said hydraulically actuated force applying means in response to log surface variations encountered.
 14. In apparatus to effect displacement of an element selectively between a normal intermediate position and either of two other positions oppositely offset from said normal position, floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the element to permit displacing the element thereby, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the first-mentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for normal positioning of the element, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment.
 15. In apparatus to effect displacement of an element selectively between a normal intermediate position and either of two other positions oppositely offset from said normal position, floating cylinder means having physically joined separate compartments each slidably incorporating therein a separate piston, means physically connecting one such piston to the element to permit displacing the element thereby, means physically anchoring the other such piston against motion, source means for providing fluid pressure, and selectively operable control valve means with associated connections alternatively selectable between said source and the respective ends of said compartments including a normal set of connections in which pressures in the respective ends of the two cylinder compartments drives the first-mentioned piston to a limit position in one direction relative to the cylinder means and the cylinder means to a corresponding limit position relative to the stationary piston for normal positioning of the element, a first alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of one such cylinder compartment, and a second alternative set of connections reversing the normal relationship of fluid pressures in the respective ends of the other such cylinder compartment, said valve means further including neutral-seeking means acting automatically thereon for retaining the normal set of connections and thereby the element to normal position. 